Production fluids from oil and gas wells typically have a sand content, along with other contaminants and particulate matter. As the solids content of the production flow is abrasive and causes wear on equipment, as well as not being desired in the final product, sand trap devices are employed to filter sand from the production stream. U.S. Pat. No. 2,125,532 teaches a strainer for separation of contaminants from a continuous flow.
When formation conditions are appropriate, hydrocarbon producing wells are stimulated by fracturing the formation with sand, a technique known as “fracing”. For this fracing procedure, very fine abrasive sand is used. Problems are being experienced with some of this fine abrasive sand appearing, without warning, in well production. The problem is not apparent until it manifests itself and sand starts appearing in the equipment. When it occurs, it can be difficult to determine whether the formation is merely “burping” small amounts of sand periodically or whether there is a more serious sand problem requiring a sand separator. The problem cannot be ignored. Even when present in small quantities, sand can damage equipment. When present in larger quantities, abrasive sand can wear through pipes and cause serious problems resulting in leakage into the environment and the threatening the lives of oil field workers.